CASE REPORT Open Access

Ventricular tachycardia observed duringcesarean section in a patient withoutstructural cardiac diseaseMika Nakanishi*, Kaoru Masumo, Takako Oota, Takeshi Kato and Toshihiro Imanishi

Abstract

A 32-year-old gravida 2, para 1 woman without structural cardiac disease was scheduled for her second cesareansection under combined spinal and epidural anesthesia (CSEA). She had stable hemodynamics after delivery;however, 16 min after the application of uterotonics, ventricular tachycardia (VT) with a heart rate (HR) of 150 bpmappeared. VT lasted for <30 s, and her hemodynamics remained stable. Ventricular arrhythmia frequently appearedfor 3 min, and the HR at sinus rhythm was approximately 90 bpm. After the discontinuation of oxytocin, VT did notreappear. A postoperative 12-lead electrocardiogram showed first-degree atrioventricular block, but echocardiographyperformed 2 days later did not reveal any structural abnormalities. Autonomic nervous imbalance induced by CSEA,ephedrine, and oxytocin, as well as ergometrine may cause intraoperative VT during cesarean section in patientswithout structural cardiac disease.

Keywords: Ventricular tachycardia; Cesarean section

BackgroundVentricular tachycardia (VT) is often observed duringanesthesia. Arrhythmias lasting >30 s (sustained VT)may cause unstable hemodynamics and require treat-ment. Although there are some reports documentingthe presence of VT during cesarean section, in mostof these cases, VT was caused by the patients’ cardiacdisease [1–3]. We report the case of non-sustainedVT without structural cardiac disease under combinedspinal and epidural anesthesia (CSEA) during cesareansection.

Case presentationA 32-year-old gravida 2, para 1 woman, weighing 56 kg,was scheduled for a repeat cesarean section which wasindicated because of a previous cesarean section 3 yearsback. The previous cesarean section was performedunder intrathecal anesthesia with hyperbaric bupiva-caine. Oxytocin (5 units) and methylergometrine maleate(0.2 mg) were administered intravenously as uterotonicsafter the birth. Anesthetic complications were not

observed. She had also undergone resection of an ovar-ian cyst at 16 weeks of gestation under CSEA usinghyperbaric bupivacaine and ropivacaine. Anestheticcomplications were not observed, and the progress ofpregnancy was uneventful. A preoperative examinationconducted before the second cesarean section revealedno signs or symptoms of cardiovascular disease, and shewas classified as American Society of Anesthesiologists(ASA) physical status class 1.After an epidural catheter was inserted at the L2-3

level, hyperbaric bupivacaine (11 mg) was intrathecallyadministered at the L3-4 level. Eight minutes after thestart of spinal anesthesia, ephedrine (8 mg) was intraven-ously injected because the blood pressure (BP) fell to 85/30 mmHg (Fig. 1). Her hemodynamics recovered imme-diately, and 10 min after the start of spinal anesthesia,epidural anesthesia (0.2 % ropivacaine 5 ml/h) was initi-ated. Seventeen minutes after the start of anesthesia, thechild was delivered. After the birth, oxytocin (5 units)was mixed in a crystalloid solution (500 ml) and deliv-ered intravenously over 30 min along with methylergo-metrine maleate (0.2 mg) injected over 10 min (Fig. 1).Sixteen minutes after the start of oxytocin and methyler-gometrine maleate, VT appeared. She complained of

* Correspondence: mikadairisa@gmail.comDepartment of Anesthesia, Osakafu Saiseikai Noe Hospital, Fruichi 1-3-25,Joto-ku, Osaka City, Osaka, Japan

© 2015 Nakanishi et al. Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, andreproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link tothe Creative Commons license, and indicate if changes were made.

Nakanishi et al. JA Clinical Reports (2015) 1:23 DOI 10.1186/s40981-015-0019-0

palpitations but was fully conscious. The longest periodof ventricular rhythm lasted for 49 beats, and the heartrate (HR) was 150 bpm. Ventricular arrhythmia fre-quently appeared for 3 min (Fig. 2). BP during thearrhythmia was approximately 110/50 mmHg, and theHR at sinus rhythm was 90 bpm. Pulse oximetry showedoxygen saturation (SpO2) of 98 %. The anesthetic levelwas at the T4 dermatome. The injection of methylergo-metrine had been completed, but the intravenous

oxytocin infusion was still ongoing. After the appearanceof arrhythmia, the oxytocin infusion was stopped imme-diately and the arrhythmia disappeared. The total doseof oxytocin infused was 2.5 units. Temporary transcuta-neous pacing pads combined with a defibrillator wereprepared. However, she was fully conscious and neededto be sedated for their application. Before sedation wasadministered, the arrhythmia disappeared and the defib-rillator and temporary pacing pads were not used. Anti-

Fig. 1 The anesthetic chart.

Fig. 2 Intraoperative ventricular tachycardia (VT) appeared 16 min after the start of uterotonics in II-lead ECG. The longest VT lasted for 49 beats,and the heart rate (HR) was 150 bpm. Ventricular arrhythmia frequently appeared for 3 min

Nakanishi et al. JA Clinical Reports (2015) 1:23 Page 2 of 4

arrhythmic agents were not administered either, becauseventricular arrhythmia did not reappear. Anesthetic dur-ation was 1 h 3 min, and blood loss was 736 ml includ-ing amniotic fluid.Ninety minutes after the appearance of VT, a 12-lead

electrocardiogram (ECG) showed sinus rhythm at a rateof 60 bpm, a PR duration of 0.215 s, and no ST changes.In comparison with the preoperative PR duration, thepostoperative PR duration was longer, suggesting first-degree atrioventricular (AV) block. Methylergometrinemaleate (0.4 mg) was administered intravenously for10 h after the surgery. During the following 24-hperiod, continuous ECG monitoring did not reveal anyventricular rhythm. A blood test performed 18 h laterrevealed normal electrolyte concentrations. Echocardi-ography performed 2 days later showed no structuralcardiac abnormalities. The patient was discharged onpostoperative day 8 without complications.

DiscussionVT needs to be distinguished from supraventricular tachy-cardia (SVT) with aberrant conduction or bundle branchblock. VT lacks the preceding P wave at the start of wideQRS waves, and atrioventricular dissociation is a differen-tiation point of VT from SVT. In this case, wide QRSwaves with no preceding P waves and atrioventricular dis-sociation strongly suggested that the arrhythmia was VT

(Fig. 3). VT observed in this case lasted for <30 s. Becauseof the short duration and the stable hemodynamics, thepatient did not require any additional treatment.Ergometrine is broadly used in coronary angiography

and echocardiography for the ergonovine testing of cor-onary vasospasm [4, 5]. It may cause AV block and VTalong with coronary vasospasm as a consequence of theischemic impulse conduction system. In this case, STchanges were not observed. Postoperative infusion ofergometrine did not induce ventricular arrhythmia orST changes. The rapid intraoperative infusion of ergo-metrine may have caused ventricular arrhythmia; how-ever, the relationship between the coronary vasospasmand the arrhythmia in this case is unclear.Oxytocin is also related to hemodynamics. Oxytocin-

induced QTc prolongation is an indirect mechanism;however, oxytocin is known to affect the autonomic ner-vous nerve tone and the duration of cardiomyocyte repo-larization and may induce arrhythmias [6]. In this case,the postoperative ECG revealed normal QTc duration,which contradicted the expected finding of oxytocin-induced prolongation.Ephedrine is a sympathomimetic that has both direct

(alpha and beta receptor agonist) and indirect (release ofnorepinephrine from presynaptic nerve terminals) mech-anisms of action. It has a slow onset of action making itdifficult to titrate the dose [7, 8]. The duration of action

Fig. 3 Wide QRS waves with no preceding P waves and atrioventricular dissociation strongly suggested that the arrhythmia was VT. Green triangle: Thestart of wide QRS waves lacked the preceding P wave. The sinus P waves thought to be hidden by wide QRS waves are shown by the green arrow aswell. Black arrow: Sinus P waves. The fourth P wave (orange arrow) was not judged to be connected with the following wide QRS wave, suggestingatrioventricular dissociation. The fourth P wave (blue arrow) was not judged to be connected with the following wide QRS wave, because of its shorterPQ duration than usual. Atrioventricular dissociation was suspected

Nakanishi et al. JA Clinical Reports (2015) 1:23 Page 3 of 4

is approximately 60 min [8]. There is a case report ofVT during general anesthesia, which is thought to havebeen caused by autonomic nervous imbalance becauseof a combination of ephedrine administration, insuffi-cient anesthetic depth, neostigmine, and epidural block[9]. In this case, VT appeared 25 min after the adminis-tration of ephedrine. Ephedrine administration andarrhythmia could be related.CSEA was performed in this case, but the total dose of

local anesthetics was low, and local anesthetic-relatedtoxicity was ruled out.Oxytocin and ergometrine were administered during

the previous cesarean section without complications.Using Naranjo’s adverse drug reaction probability scale[10], we obtained scores of 2 for ergometrine and 4 foroxytocin, which make them possible causes for theevent. Autonomic nervous imbalance induced by CSEA,ephedrine, and oxytocin, as well as ergometrine, a vaso-constrictor, may have caused the arrhythmia in this case.

ConclusionsAutonomic nervous imbalance induced by the combin-ation of CSEA, ephedrine, and oxytocin, as well as ergo-metrine may cause VT in a patient without structuralcardiac disease.

ConsentThe patient’s consent to publish this case report was ob-tained and documented.

Competing interestsThe authors declare that they have no competing interests.

Authors’ contributionsMN anesthetized and examined the patient after surgery and wrote thisreport. KM, TO, and TK examined the patient preoperatively. TI examined andanesthetized the patient 3 years previously. All authors read and approvedthe final manuscript.

AcknowledgementsWe would like to thank Enago (www.enago.jp) for the English languagereview.

Received: 27 July 2015 Accepted: 23 September 2015

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